The article provoked a very interesting career-related question. It has already been more than 7 years since the probe launched, and altogether it will be 9.5 years by the time it arrives at Pluto. How does one choose to take on a project that will take a big chunk of a career to start yielding data? The news article provoked the question, but it didn't answer it. So I wrote to Stern on Friday; he wrote back over the weekend.

If Stern were funded by the National Institutes of Health, he would have had to renew his grant five times.

Yes, Stern writes, the probe will take 9.5 years to arrive at its destination. But his involvement in the project is much longer. "I should caution that we've been working on it since 1989, got it approved in 2001, and funded in 2003. Launch was in 2006; we arrive in 2015." That's 26 years from the project's initiation until the data start coming in. If Stern were funded by the National Institutes of Health, he would have had to renew his grant five times. He continues:

I was pretty young, 31, when we started on this. I am now 55. So I think I know something about what you're asking about. One has to make a judgment about getting involved in projects this long. In my case, it was pretty easy—the exploration of a new planet and a new type of planet was a scientific gem in my eyes. I consciously decided to devote a big fraction of my career to it, knowing that if we were successful, it would be an amazing scientific accomplishment and contribution—well worth the years. I still feel that way.

We are not training replacements for my New Horizons team, but we are full of young people, from postdocs in their 20s to engineers, flight controllers, and scientists in their 30s and 40s. The science team's average age—i.e., those of us who started this, is near my age, or a little older, but a lot of much younger people will be sharing in the excitement, the research, the publications, and the limelight when we get there.